The medical term for waist rotation (i.e. rotating the shoulders beyond the hips) is trunk axial rotation or trunk twisting and seems to be well known as a major risk factor for chronic lower back pain in most papers. 

Many table tennis players have chronic lower back pain and I suspect it's due to the overuse of waist rotation as a power source in our sport. Maybe it's time to reevaluate our techniques to eliminate the reliance of waist rotation (on the FH it's a pure leg driven hip rotation with the shoulders, hips and knees always in line with one another; BH it's squatting/unsquatting, bowing/unbowing similar to a deadlift)? As I know the CNT has already done a 180 degree on its views on waist rotation, now they think it is no longer reasonable (evidence by prominent members like Li Sun, Guo Yan in tutorial videos, Ma Long changing his strokes significantly).

I have put some medical papers I've read here (not a full list): 

http://injury-forensics.com/wp-content/uploads/2016/11/An-electromyographic-study-of-isokinetic-axial-rotation-in-young-adults.pdf" rel="nofollow - http://injury-forensics.com/wp-content/uploads/2016/11/An-electromyographic-study-of-isokinetic-axial-rotation-in-young-adults.pdf

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3777056/" rel="nofollow - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3777056/

I know this is a very controversial topic, but let's get it out and discuss this!  

I'll be the second believer, and I'm gonna take a week or two hiatus to focus on shadow practice to unlearn the waist rotation from my techniques. Thanks zeio and sorry for ignoring your posts the first time around!

Zeio's posts are here:

http://mytabletennis.net/forum/harimoto-forehand-technique_topic83198_post1033307.html#1033307" rel="nofollow - http://mytabletennis.net/forum/harimoto-forehand-technique_topic83198_post1033307.html#1033307

did you mean that?

http://mytabletennis.net/Forum/forum_posts.asp?TID=83198&PID=1033307&title=harimoto-forehand-technique#1033307" rel="nofollow - http://mytabletennis.net/Forum/forum_posts.asp?TID=83198&PID=1033307&title=harimoto-forehand-technique#1033307

Yes fatt that is the more correct link... Tbh zeio was really understating its importance, given that chronic lower back pain is a condition that is really terrible, I know a few people around me who have it and honestly it's a life of pain. 

There was a necroed thread, it was hard to read personally...

http://mytabletennis.net/forum/back-pain_topic36105_page1.html?KW=Back+pain" rel="nofollow - http://mytabletennis.net/forum/back-pain_topic36105_page1.html?KW=Back+pain

I also think it is because of todays tabletennis. Almost more backhand today than forehand and the game goes faster, more players play closer to the table. So i think this also can be a reason for less torsorotation. We Do not have the time and space anymore. 

http://www.rebuildyourback.com/herniated-disc/twisting.php" rel="nofollow - https://www.rebuildyourback.com/herniated-disc/twisting.php

Hmmm.... this is interesting.   I have been trying this recently and wondering why my back is unusually sore.  Just being aware is helpful.

I do not think the body is made for this kind of ratiation, and repeteive motions. And the plastic ball proably made it worse. 

They need to do more work on the ball.  

I can sort of visualise that... if you drop your shoulder when looping (ie if your shoulders are not on the same height), you bend your trunk which  results in a significant compressive force on your lumbar on the right side  in addition to twisting, pretty much the worst combination. 

The site I linked pretty much identifies compression and twisting as the major aggravating factors for lower back pain.  

It is common, but there's plenty of old people without lower back pain who don't play table tennis, and a lot of younger adults who play table tennis frequently who developed chronic lower back pain at a younger age.

I think a careful scientific study is required to assess this, but that is solely my hypothesis, seeing how common lower back pain is in our sport, and the mechanisms do match (trunk rotation and bending). Table tennis involves lots of repetitive actions especially those who train over a lifetime, and one of the primary mechanisms for producing power is trunk rotation and bending which has already been proven and identified as harmful in medical literature. 

I would say that the trunk rotation and bending in forehands being a lot more damaging than that in the backhand because we tend to produce more power in the FH compared to the BH.

If you drop the shoulder without dropping your hips, you induce bending (if you ever studied structural engineering that produces compression on one side and tension on the other side, which can be quite significant depending on how much you bend). It is no wonder that Timo Boll had so many issues with the lower back. 

If you rotate your waist without rotating your hips, you induce torsion in your lower back. From the website directly, a good analogy is if you have a dishrag, you can twist/wring the rag (the discs) which causes the water (the nucleus) to seek a way out. Of course if you bend you directly compress the liquid on one side which also causes it to seek a way out.

Now the discs are actually quite strong, but aggravating it for a few million cycles, and it may start to break down. It's basically fatigue failure which also happens in many structures (road pavements being the most common)

Yes, players who rely less on the waist would protect their waist better. If you don't rely on power from the waist you have to compensate elsewhere, and it's normally the legs. That or get faster equipment lol...

http://www.researchgate.net/publication/283327383_Low-back_pain_in_table_tennis_players" rel="nofollow - https://www.researchgate.net/publication/283327383_Low-back_pain_in_table_tennis_players

It's a very short article, but has some scary statistics.

 145 table tennis players were randomly selected from the Hellenic Table 

Tennis Union and answered in questionnaire that included 32 questions concerning general health, work history, education and physical exercise. The questionnaire was validated with intraclass correlation coeffiecient (k=0,644 -1.00, p<0.05, <0.001 respectively). There was no statistical differences in quantitate data among personal factors (age, height, BW 

and years in sport participation), between the tennis players with and without LBP. Concerning the prevalence of LBP among participants. 74 players (51.2%) had LBP some times in their lives before 

the survey. 34 tennis players had mild pain, 65 had moderate pain, needing no rest and 23 had severe pain. As to the associative problems to the limps, 23 players had no symptoms, and 54 had radiating 

pain to the lower leg. 52 tennis players reported that taking physiotherapy, 22 resting or taking a bath, and 55 using TENS improved their LBP. Correlation between qualitative data of personal factors and LBP was significant higher among tennis players that answered yes to the item hard training, than the players that did not. There is no correlation to the other qualitative data of personal factors for the prevalence of LBP.

Edit: after more tries with core bracing, I found something magical! If you brace your core well, you can activate thoracic rotation (rotation at the chest) without lumbar rotation (rotation at the lower back). This is much safer than lumbar rotation as you can see from the video below:

Perhaps Harimoto is using something similar and is in fact not rotating at the waist but at the chest?! If that is the case, I suspect he indeed has the most advanced biomechanics of any TT player indeed!

Despite the disdain for technical jargon, I think you've got it (disabling waist/lumbar rotation and replacing it with the healthier thoracic rotation)!  

I feel like with all habits, it's gonna take some time before it sinks into our subconscious which we can then integrate into our game. But, we've only got one body to work with, and for me at least the pain of having to retrain my technique definitely would be less than chronic lower back pain later on in life!

Thoracic rotation will surely cause rib problems.

It's very obvious that in the screenshot above, Harimoto's shoulder axis is rotated about 30-45 degrees more than his hip rotation, however it is still healthy because he is bracing his core (no waist rotation) very well (as seen by how straight his waist is), the rotation is at the chest (thoracic rotation) which is much healthier than waist rotation. 

I think given these, Harimoto, in fact has one of the healthiest and most effective techniques out of the current pros! I completely take back my previous criticisms of Harimoto's FH technique.

I understand that change could potentially be very hard (given that waist rotation, dropping shoulders has been in coaching literature for decades!), but sometimes we do have to change our minds when the facts change! 
 

Oh I've no doubt something will have to give... doesnt matter what technique you use, but probably depends on your body and which area is strongest for each person 

Our situation is not as bad because we have viable alternatives such as thoracic rotation. The NRL has finally had to face the overwhelming evidence that rugby players are prone to highly damaging concussions, and I'm not sure what has changed in the sport since then. I hope with the table tennis community we do not bury our head into the sand and ignore this issue just because "it's the way we have always done it"! Our collective lower back health as a community is far too important an issue to ignore...

Not sure anyone is saying that... only that if you start rotating at the thoracic spine, then it will suffer as a result. Just because you cease lumbar movement and stop lower back pain, doesn't mean that another type of injury won't crop up from using the thoracic 

The only problem with that argument is that the thoracic spine has a completely different structure compared to the lumbar spine which allows it to rotate sustainably unlike the lumbar region. If people have watched the video or read the articles they would understand. 

Hi serr, thanks for the post! Firstly I would advise you to take some rest and  stop TT if you have lower back pain! But to learn the technique, firstly you need to know how to brace your core effectively (those who had strength training experience will know, otherwise there's quite a lot of resources on youtube or google), once you brace your core, your waist is gonna be like a hard rock. Without the core bracing everything else will fall apart! Once you start bracing your core, you will disable the harmful waist rotation. Then, with that as a foundation you can rotate your chest and your shoulders without rotating your waist. Combine that with leg driven hip rotation, and you have the stroke down. 

To answer your question more directly, your hips, waist and chest are three different areas. You rotate at the hips, stiffen your waist (brace your core), and rotate more at the chest. 

If you do it correctly you're gonna feel like Mike Tyson delivering his signature hook punch...

Speaking on deaf ears no doubt, but resting for a few days or even a week is much shorter than recovering from an injury... 

Take it from some idiot who disregarded that advice too many times! 

Along with advocating waist rotation, the Chinese also emphasized core stability and contraction, which is required to transfer power from the hips to the upper torso. In other words, it's not like players weren't tightening their cores before.

Vertebrae sure gets smaller and more delicate if you will, further up the back. Thoracic rotation requires engaging and tightening more upper back muscle. I'm not sure shifting rotation upwards is a better alternative.

I'd suggest freeing up your hips by letting your feet rotate on their toes, the left on the backswing and right on the followthrough (righty FH), as opposed to keeping your soles planted throughout the stroke. When you plant your feet sole down and stay there, you in turn lock your knees, thighs, and hips in place, as opposed to rotating with your upper torso.

Avoid the scenario of a fully opened stance: you're square to the table, with feet apart, toes aligned, and hips also square to the table, and you keep your feet planted while rotating your shoulders back to take the paddle back.

Just minimize winding up your spine like wringing a towel. Contract your core to keep the hips and shoulders aligned as much as possible.

+1, a free hip rotation (through freeing the legs) and core bracing is the basics here, but waist rotation is proven to be bad regardless of how you do it, the injury statistics and medical articles don't lie... It's time to admit that the Chinese coaching literature has been wrong for decades!

The consensus in the medical community seems to be that thoracic rotation is safe. For e.g boxing uses extensive use of thoracic rotation and they hit with much more violent acceleration than any TT player, I haven't heard of them getting rib or upper back injuries due to this overuse of thoracic rotation (happy to be  proven wrong but so far this seems to be the case). Thoracic rotation also helps take up some load which will reduce the demands on the hips, which i believe to be safer. Also, thoracic rotation has a lot of range of motion, which makes the strokes a lot more speedy and powerful compared to just relying on hip rotation. From what I experience, activating thoracic rotation is also a great cue to brace your core, because you can't do thoracic rotation without core bracing (the lumbar will always rotate first if you don't brace it). 

So far Harimoto is the only one using thoracic rotation on the circuit, it seems to be his best kept secret indeed! He and his parents are geniuses for having made this decision long time ago, which is why I believe Harimoto has a technique advantage over the CNT which is stuck in waist rotation land (and just realising that it is harmful). I'm not sure if they have shared the knowledge with other Japanese team members since they don't seem to be using it....

This is great advice, I would add that active core bracing will help a lot in disabling the waist rotation (you can't rotate it while you've got it locked in place hard), for those who have been using waist rotation for long periods of time like me, it is quite helpful to have this "cue". 

You're right I probably digressed...sorry couldn't resist it! 

His FH is very underrated, he takes the ball early and reloads really fast compared to those who use waist rotation...in terms of power it is already quite powerful compared to kids his age and size (he doesn't exactly have a powerful build)... If someone with the build of Fan Zhendong or Liang Jingkun uses thoracic rotation it would be doom for the rest of the world lol...

I don't think the Chinese can overhaul their coaching system and literature that fast, they've been caught unaware yet again! The fact that they have no one in the team using thoracic rotation shows the limits of their knowledge.

Having said that, I already have a lumbar issue (herniated disc) which kept me from using the forehand at all for a long while. I'm really liking the new thoracic shadow training so far. I can feel there is less tension on the spine because it's not being torqued around like a merry go round! I think I'm having trouble getting the hip into action... any videos or techniques to get that part going correctly? I feel the upper body rotation is going fine, but the hips dont really turn unless I move the lumbar with them. I've tried turning with the lumbar, then rotating the lumbar back while keeping the hips stilled rotated. Just feels weird 

Edit: I would think that boxing probably had a similar issue that you have to brace your core for long periods of time...

Hahahaha obesechopper you're right I haven't exactly been sleeping well, this has been one of the most exciting discovery I've ever had. I slept at 1am yesterday coz I couldn't quiet my mind lol....I have never managed to do thoracic rotation ever in my entire life!

Imo the foot and knee movement seems to be very key to the hip rotation, I don't do it that well personally tbh, would be good if Ttgold were able to do some simple demonstrations (maybe even without a paddle) to illustrate how to train the hip rotation and mobility in the FH. 

I do these antirotation exercises at the gym regularly to train my core bracing, because I have minor scoliosis the demands on my core when doing squats are greatly amplified... I always do them at the start to warm up  my core before major lifts.

Edit: Would say that these antirotation exercises are an extremely low risk way to train up core bracing. I personally found them extremely useful. (With squats, deadlifts, pullups you have too many other things to worry about). 

I haven't used any braces before personally, but I've seen people use them for squats, tbh it's a good idea, maybe I should use them (for me my core is always the bottleneck, never the legs, using them will lessen the load on my core so I can load up more on the squats without that much fear)

Following this thread of thinking led me to do some research on breathing in boxing. In fact breathing is viewed as extremely important in boxing. 

http://www.expertboxing.com/boxing-techniques/body-movement/breathing-techniques-for-fighting" rel="nofollow - https://www.expertboxing.com/boxing-techniques/body-movement/breathing-techniques-for-fighting

From what I gather it's a similar issue in boxing, if you exhale you lose the bracing effect which is also very important in boxing. So there's some degree of air management that's necessary to maintain the core bracing well.  

In TT, it looks like the core bracing is crucial both during the backswing as well as the stroke itself, but you gotta exhale and inhale otherwise you don't get enough oxygen to do these explosive movements. You can't just synchronise your breathing with your strokes because the rhythm of the strokes can be quite irregular (can be fast, slow etc...) while you can't really compromise with your breathing. 

From the article above it seems like boxers inhale through the nose whenever they need to (inhalation is normally not a problem because it increases the core bracing effect), but the exhalation is through the mouth with a pssst or psshb sound which is designed to shut off air flow out of the mouth (losing air is bad because you lose the bracing effect). The exhalation is usually timed with the punch (in TT I would expect to do the same for a stroke). You exhale each a bit each time you do a stroke and not necessarily inhale again, until you feel the need to inhale, then you breathe deeply from your nose. 

To be honest this is all new to me, I'm not even sure if I got it correct? I'm quite sure there's members over here with experience in fighting who can provide some better advice here...  

Edit: watched a bit more videos... seems like the inhalation is something the body does naturally, exhalation is where the technique comes in... will try it some time!

Edit: I tried some of the techniques myself and I think I'm starting to get it, so TT before your first stroke you have to breathe deeply in, then you do a short and sharp exhale with little air every time you do a stroke, and breathe in  deep again whenever your body tells you to. So most of the time the tank is full of air and hence your core is braced effectively most of the time.

This part of racquetsforsale's post reminded me of that. I recorded the session so maybe I'll add a video when I have time. I wonder what others think about it.

racquetsforsale wrote: I'd suggest freeing up your hips by letting your feet rotate on their toes, the left on the backswing and right on the followthrough (righty FH), as opposed to keeping your soles planted throughout the stroke. When you plant your feet sole down and stay there, you in turn lock your knees, thighs, and hips in place, as opposed to rotating with your upper torso.

Interesting. I was going to comment earlier on that exact passage of racquetsforsale's. When I shift my weight, as described above, my hips and waist are naturally aligned. I have no idea whether that's good or bad, but that's what they do.  

That video of TtGold, I think, illustrates what racquesforsale described.

Please do upload the video, I think it will be quite helpful!

1:

2:

Yep he definitely has good foot rotation going on. Btw this could also explain why Waldner had lots of lower back issues, he drops his right shoulder (trunk flexion) and rotates at his waist too (trunk rotation)...

He mentions at the very start there are 3 timings with the foot "leaning" towards the outside, in the middle then "leaning" towards the inside. Off memory earlier when he did it, he mentioned contacting the ball during the middle one.

It's likely he's over exaggerating it for demonstration purposes, but it's interesting because it's not just going for mostly flat foot to having the heel up with weight finishing on the front of the other foot.

As for the translation, I didn't mention anything that they didn't say. It definitely looks like hip rotation, but they didn't mention it specifically. They talked about rotating the body as if your body was a rod. So more like whole body rotation without leaning towards one side.

Wow amazing demonstration! Very clear indeed....

I never thought about the rotation about the heel...so rather than a binary system 0 or 1, it's a continuous smooth movement of the heels to enable the hip rotation...

But... most importantly my lower back felt so good bracing it all night (usually I will have a bit of lower back soreness, but tonight I just felt amazing there).

Interesting choice on your coach's part to demonstrate that. I've noticed players, both amateurs and pros roll on their back foot like that when hitting in place. I've seen clips of FZD doing that, but can't find that clip, but here's a very high level amateur doing it. He's got a monster FH by the way. Long video, so you have to seek to see the part with the side view of him hitting.

I just think these guys have very young and flexible ankle joints that can accommodate the slight rolling action. I've never thought the rolling actually contributes to the stroke quality. Therefore, it's important to know the context in which your coach shared this information or, if he indeed does, why he believes it's crucial to roll the foot like that at all. Other than warming up in place, more often than not, players don't nail and roll on their back foot like that.

You should read about the valsalva maneuver, used extensively in weightlifting and powerlifting but really relevant to any sport where you need to stablisis the trunk.

also it got me thinking to the forehand loop videos of harimoto, ma long, fan zhendong, and zhang jike

from the looks of it, it looks like zjk is the only one that keeps his feet more pointed forwards, with little flaring to the side, whereas fzd flares a little bit, and ma long and harimoto pretty much make their right foot parallel with the table (right foot pointing right)

is it a coincidence that zjk is the one that is pretty much washed up due to injury of his lower back?

although, with ma long's recent knee injury... it seems like injuries are just a matter of time for all athletes 

Yep the core bracing I used is pretty much the Valsalva maneuver I learnt in powerlifting, which is why I was talking about air management, you can't do a Valsalva without air in the diaphragm....

So I borrowed the boxing breathing techniques of breathing in deep before the point to perform the Valsalva, and then exhaling just a sharp burst of air with every exertion making sure to lose only a little air to maintain the Valsalva, and after about 5-6 exhalations when I'm left with about 50% air in the tank I breathed in deep again to strengthen the Valsalva again... This makes sure that my core is braced pretty much all the time and I'm able to get more than enough air.

Edit: I can see why Harimoto likes to shout lol...he's been trapping air inside his diaphragm for the entire point! It would feel good to let it all out in a shout hahaha....just joking of course

You can see ZJKs issue, he drops his right shoulder putting his trunk into flexion placing huge compessive forces on his right lumbar. It seems that Waldner, Timo and him do it a lot which explains why their lower backs have been damaged a lot more than other players. Fan Zhendong is mostly hip rotation with a bit of waist, Ma Long used to do waist rotation but he fixed it and now it's almost a pure hip rotation. Harimoto is the only one on the tour doing thoracic rotation, his waist is locked very tight if you look at the videos. Thoracic rotation has a signature, the shoulders will rotate about 45 degrees more than the hips (this is impossible with waist rotation) leaving the elbows very visible from the front view during the extreme end of the backswing,  also you can see a clear straight line through the waist and hips. I did mine in the mirror and it looks exactly like Harimoto...

That guy looks a lot like a 2700+ player that was in the US for a while.

https://www.youtube.com/watch?v=wTXchLpG5Ck" rel="nofollow - https://www.youtube.com/watch?v=wTXchLpG5Ck

Hi fatt, the gym belts are way too heavy for TT, instead I tried an effective low tech solution last night. With your exercise shorts tighten the strings hard at the  waist so that it exerts a compressive force onto your waist, this helps in bracing the core and also you can feel it anytime you try to engage the waist.

i definitely had a low backswing, dropping my shoulders and i didn't even make the shot and injured myself 

at this point that was like four to five years ago but the injury still haunts me

moral of the story is try to not have lower back flexion to prevent injury?

but then when looking at professional players looping against backspin, there is always going to be some level of dropped shoulder... but i guess the knees are bent low enough and the lower back is kept straight enough to not cause injury?

Thanks for the honesty in sharing your experience, as you can see players who dropped their shoulders often (Waldner, Timo Boll, Michael Maze, Zhang Jike) all eventually destroyed their lower backs. Professional and amateur players have been using the medically unsafe technique for decades. You can loop backspin without dropping your shoulders, by using the biggest muscles in your body ie your quads. 

Ideally youd almost want the opposite to this imo. Baggy waist that you have to brace into to stop your shorts falling down...lol. That's literally all weightlifting belts are for btw. Contrary to common belief they do no supporting of the lower back whatsoever themselves, it's the bracing of the abs against the belt that does the supporting.

Wait what? That's mindblowing...so you're saying that actually it's my core that has been doing all the work and the tightened shorts didn't exactly help haha...it did serve a useful purpose though, having it tight makes it such that whenever I tried to rotate or bend my waist (bad habits die hard) I rub against the fabric which tells me I'm trying to do an illegal movement lol...

I believe you're correct, judging by the pair of moles and his ears.

Amateur in the sense that he doesn't play on the pro tour for a living. The amateur field in China is very deep indeed.

How come he s amateur?

What about wearing one of the neopreme elastic fabric belts designed for lower back issues? I got one and I am going to try it out. I think it will give me feedback when I do waist rotation that could be helpful.

Haha that's a bit extreme but I reckon it'll do the job of giving you useful signals!

Quite a lot of veteran players use this type of thing.

http://www.mytpi.com/articles/fitness/5_exercises_for_increasing_thoracic_spine_mobility_in_your_golf_swing" rel="nofollow - http://www.mytpi.com/articles/fitness/5_exercises_for_increasing_thoracic_spine_mobility_in_your_golf_swing

That's sad to hear :( if you really love the game then retraining to adopt healthier techniques could be possible but will take some time. (That said it didn't take me that long to adopt thoracic rotation, just a week of shadow practice and one or two practice sessions)...

Knee issues could be due to inadequate rotation at the feet to support hip  rotation, like what many ppl said here...

I was having some issues with the backhand chop as well. What worked better for me was moving my feet first and actually going toward the ball, instead of staying planted and reaching out, twisting to contact the ball. That allows a more neutral spine on most of the shots and only on the very hard ones do I have to reach for. Doing so I changed the ratio though from twisting on most shots to maintaining a neutral spine on the majority 

The only thing he's still recommending which is bad is dropping the right shoulder which is demonstrably unhealthy for the lower back...

He also demonstrates rolling the feet similar to mickd's video, and the way to push off the right foot, which is the same way that a basketball player pushes off the ground to make a slamdunk, and looks exactly like a kickboxer initiating a kick (hint it's not pushing off the heel!). Apparently he's saying that NBA players can produce a ton (1000kgf) of force just from that action alone. 

Edit: the best analogy of the push off i can think of is like going to a tiptoe position for your right foot. Checked a bit further and it's basically mobilizing your calves to help out. 

For the hip rotation, he says that many amateurs think of a more translation movement but aren't actually rotating, it's the rotation which is the most important and you can demonstrate it easily by tying a rod to the hips lol...

He also demonstrated an exercise for hip rotation using resistance bands which the CNT apparently are using, focusing on the hip rotation (you have to brace your core hard for this), the argument is that it's easy for us to do it wrong in table tennis because the ball is so light, once we increase the load it's more likely that the more inefficient methods will be eliminated)

Shot quality wise, I'm still tinkering to get my body working in unison (without overthinking and slowing down the movement...) but the loops and such are still quite powerful when needed. I don't feel any real loss of force when playing. The only short term problem I face now is the occasional brain lapse where I freeze before starting the stroke and wonder which part I'm supposed to be moving! Just try to remember, squeeze the gut and rotate the chest! 

Glad I'm not the only one enjoying the benefits :) Same for me, I used to have some lower back soreness after playing, it just disappeared after I started to do thoracic rotation! Btw, this is a really fast switch of technique  Next on the list will be the hip rotation hahah....

Hi fatt, yes this is indeed the case to ensure that we're not hurting our lower backs!

No worries fatt, i felt that it's definitely something important to acknowledge in the sport! Would definitely recommend making this thread a sticky to spread the knowledge more widely.

Btw am curious how are you bracing the core, I've been using the Valsalva maneuver which tbh maybe is too overkill and not the best way for TT (I had a blocked nose yesterday and didn't know how to breathe properly at all). Do you just contract your core  muscles without sucking in air?

During match play, you'll probably be out of position, so you'll end up rotating certain parts more or less depending on the incoming shot.

But during practice, keeping it all together seems like a safe compromise.

Also, maybe this is why I've heard Ishikawa Kasumi in the past say to tighten your core during shots.

The part where you are pretty much forced to engage in either waist rotation or thoracic rotation is when you're jammed at your elbow and you got no time to move your legs out of the way....

I've been working on the same thing. When I train with the robot for 30+ balls in a row, I kind of get a headache from the breathing method where it raises blood pressure. I'm experimenting with doing a sort of Dima moan each shot, to ensure I get the airflow release lol... but a bit quieter. And relaxing the core just a fraction, seeing how much I actually need to flex for it to be effective without going to the point where I'll pass out mid rally! I breathe in before the pull back and expel during the swing. 

It's still going through the conscious phase, where I have to actively think about rotating the thoracic and not the lumbar each shot. Some times I can get it going where the flow is becoming natural, and during those portions I don't really have to tense the core much at all. Just slightly. When I over-tense, I feel that's where the breathing/blood pressure issues arise. 

**also the bug is back, judging by that text... 

Same here I'm experimenting a bit of tensing the core muscles and not bother about sucking in air via the Valsalva maneuver, just breathe as usual (normally). It also found out that you can still activate thoracic rotation with less core bracing, but for me if I don't tense the core I always default to lumbar rotation (yikes!)

I'm giving it a little time before making any big changes. To my thinking, the same goes for learning every other technique. At first you're over-thinking the process and staying tense, focusing on every little detail which makes the new movement appear very stilted and robotic. Maybe given a week or two, the natural looseness will kick in and the core/body can relax as needed 

Yeah I guess we all have to go through that process :( I just did more shadow practice and just contracting the core without Valsalva still works well, in fact I only needed like 20%-40% of my max core bracing force to enable the thoracic rotation... and I could still breathe and talk properly, it was a lot more natural rather than doing the huffing and puffing all night long! Looks like I really went overkill on the core bracing the first time around haha...

And I can say this... my back (lumbar/spine) did not hurt a single time! I didn't have to stop and bend over or crouch down and stretch my spine at all. No discomfort there at all. By the end of the day I did have a few sore spots... but they were confined solely to the muscles! Those being the left obliques and some in the upper mid back from the thoracic rotating. 

That alone is a tremendous boost to me!

But to top it all off, my shots were amazing! It's like my level jumped a few hundred points overnight. Whereas before I may have felt my motion was too slow to attempt a loop or shot, so I just paddy-caked the ball back with a wristy slap... I can now execute the thoracic turn and unload a killer shot! I was hitting so many winners where the opponent found themselves still standing there in a fancy pose, having finished their shot and failing to return, while I rotated and snapped back a clean winner. Even on the move, which was my original concern, I was able to rotate the upper back and wammo! Send over blistering shots. 

I barely had any chance to chop at all unless they hit one really wide to the backhand, because my offense had taken such a dramatic turn for the better - there was simply no point for me to chop! When I could hit such great strokes, kill their timing and still not feel any pain in the lumbar region. 

I'll tell you blah, this has been a miracle change! A miracle! I started experimenting with this on the 19th, and now 10 days later... woo! I think it not only improved the quality of my game, but also vastly lengthened my shelf life playing table tennis! No issues with the breathing either. I was able to relax and rotate freely. Only "issue" was falling back to the lumbar twist during a few points, nothing big. 

This is the first time I can recall playing in, perhaps YEARS!, where I've felt no lingering lumbar stiffness and achy spine after the session ended. 

Glad it's working so well for you! I felt exactly the same way when I switched too, just amazing speed and power without any lower back soreness anymore! 

Welcome to the thoracic rotation club ;)

Thanks for the compliments